What parameter affects both the cycle length and discharge burnup in a nuclear reactor?

The parameter that significantly influences both the cycle length and discharge burnup in a nuclear reactor is the reactivity of the core. Reactivity refers to the ability of the nuclear fuel to sustain a chain reaction, which is directly related to the number of fissile atoms present and the neutron economy of the reactor.

When reactivity is high, the reactor can achieve a higher power output in a shorter period. This means that the fuel will be consumed more rapidly throughout the cycle, potentially leading to a shorter cycle length. Conversely, if the reactivity is lower, the reactor will operate at a reduced power level, resulting in a longer cycle length as fuel is utilized more slowly.

Additionally, the discharge burnup, which indicates how much energy has been extracted from the fuel before it is replaced, is also affected by reactivity. Higher reactivity allows for more efficient use of the nuclear fuel, leading to a greater discharge burnup. Therefore, the relationship between the reactor's reactivity, cycle length, and discharge burnup is integral to reactor operations and fuel management strategies.